V. Carravetta et al., Orientational probing of multilayer 2-mercaptobenzoxazole through NEXAFS: An experimental and theoretical study, J PHYS CH A, 103(24), 1999, pp. 4641-4648
Near edge X-ray absorption fine structure (NEXAFS) spectra of 2-mercaptoben
zoxazole have been investigated from experimental and theoretical points of
view, The 2-mercaptobenzoxazole molecule presents an interesting case for
NEXAFS, with its aromatic, benzene-like, fragment and its heteroatom-rich p
art, containing C, N, O, and S atoms. NEXAFS spectra of a 2-mercaptobenzoxa
zole multilayer on Pt(111) at the carbon, nitrogen, and oxygen K-edges and
at the sulphur L-edge have been recorded at normal and grazing incidence an
gles of the photon beam with respect to the surface. The C, N, and O K-edge
spectra exhibit angular dependence in the pi* resonance region, indicating
a mean orientation of the molecules on the surface. The angle between the
molecular plane and the surface has been found to be about 48 degrees. The
experimental data are discussed by comparison with static-exchange (STEX) a
b initio calculations for the different edges. Good agreement is observed b
etween experiment and theory, allowing for a detailed discussion and attrib
ution of the various features observed. A vibrational progression at the C
K-edge is also identified in the highly resolved experimental spectrum.